FIGURE 24 in Systematic revision of the trilobite genera Laudonia and Lochmanolenellus (Olenelloidea) from the lower Dyeran (Cambrian Series 2) of western Laurentia

FIGURE 24. Bivariate scatterplots depicting intraspecific variation in various aspects of cephalic morphology of Lochmanolenellus trapezoidalis n. sp. Symbols represent phases of cephalic development. 1, Orientation of the distal portion of the posterior cephalic margin (distal PCM). 2, Degree of lateral flaring of the intergenal spine. 3, Proportional cephalic width, measured as the ratio of the transverse distance between the intergenal spine bases to glabella length. 4, Posterior deflection of the proximal portion of the posterior cephalic margin (proximal PCM) relative to a transverse line. 5, Degree of lateral flaring of the genal spine, quantified as the angle between the inner margin of the proximal portion of the genal spine and the distal portion of the posterior cephalic margin (distal PCM). 6, Cephalic shape, measured as the ratio of the transverse distance between the intergenal spine bases to the transverse distance between the genal spine bases.